E8600 4.5GHz (Prime95 Stable)

mremulator

mremulator

mremulator

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Been tinkering for just over a week now with my E8600 (love this chip), anyway, just thought I'd share my findings.

Sure my E8600 will bench @ 4.6-4.7GHz, however, will fail Prime after 20 minutes or so. Increasing voltage beyond 1.35V does not seem to help and temps go through the roof.

I found that 4.5GHz (stable) requires 1.35V (1.3875V in BIOS) and will Prime (blend) for 12 hours+ on my XFX 790i Ultra.

Anything above 1.35V causes Prime to fail and temps to jump 10C+.

In addition, 1.4V FSB and 1.5V NB ensures stability.

The 790i chipset is VERY picky about voltages.

Mostly common knowledge I'm sure, but may help someone. ;)

 
The Asgard said:
Cracking overclock. Might have to check one of these chips out myself :)
Click to expand...

Yea, even the guys over at OCZ are amazed with the ReaperX 1333-1800MHz OC. :) Again, my RAM will do 1880MHz at the same timings, however, my CPU is holding it back as I want to keep things 1:1 and stable. They also pointed out that 1800MHz @ 8-7-7-24-2T is actually better than 2000MHz @ 9-8-8-30-2T, which is their current PC3-16000 offering. :D

So all in all I'm very happy with what I've got!
 
Very nice!

What batch, week etc is that?

My E8600 looks like it needs 1.44v load for 4.4Ghz, failed Prime after 8mins with 1.42v, currently 30mins in with 1.44v.
 
Looking good so far -

44ghz1hrprimeks3.jpg


Don't know about running this voltage 24/7 though? Any more opinions on that?

Some people seem to say keep it under 1.4v, some under 1.45v and some say your Ok aslong as PLL voltage is kept down?
 
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VTT is the killer.

If you plan on keeping the chip I would keep VTT/FSB to 1.2 max and keep the chip below 1.4. I would also turn LLC off that can cause some serious voltage spikes.

I tend to bench with a max Vcore of 1.35.
 
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I'm running with LLC off and PLL voltage is at default, only voltages I've increased are the Vcore, and then FSB and NB voltages very slightly (0.04v)
 
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Just checked the bios - you say keep PLL at 1.2 max? I've got it on Auto, but on manual settings the minimum is 1.5v? :confused:
 
My E8600:

Batch = Q822A435
Pack Date = 21/07/08

Anything over 1.4V for ~4.5GHz is an overkill IMHO.

More volts than that... better make sure you have some decent cooling and money for a replacement chip. :)

I'm running a single loop XSPC triple rad, Laing 18W Ultra pump and D-Tek Fuzion R2 block on my E8600 by the way. Idle temps are 38-41C and 55-60C load now after things have settled in.

Relatively low volts too compared to what I've seen.
 
VTR said:
Just checked the bios - you say keep PLL at 1.2 max? I've got it on Auto, but on manual settings the minimum is 1.5v? :confused:
Click to expand...

Sorry I mean't VTT or FSB voltage. Too much cider before lunch :D

Some people say VTT can equal Max Vcore. Its a bit of a grey area but luckily VTT never held any of my chips back.
 
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Cheers for the input!

I'll knock the vcore down and keep it under 1.4v max. I'm using a P5E board with a TRUE cooling the E8600. Going to lower the multi and see what the best combo of FSB / multi is. Think I may need to do the vdroop mod to get the most out of this board/chip as the droop is awfull at the moment.

What's the max safe voltages for each of the following if I need to up them -

CPU PLL Voltage - keep under 1.6v
FSB termination Voltage - default is 1.2v?
North Bridge Voltage - default is 1.25v?

Don't think I need to adjust any others?

So many more voltage options these days, was much easier on my E6300 and old 965 board :p
 
I would try and find your max stable FSB first. Drop your memory back and lower the multi on your chip. Basically take everything out of the equation so you can concentrate on the FSB.

Start at the lowest voltage on the NB and take it from there.

Once you have a good stable FSB then start upping the multi and adjusting Vcore.

Once you have achieved your target speed. Start on your memory.
 
Yeah that's what I'm going to do, just wanted to have a quick play around with the CPU first to see what it's capable of, now I know, I'll keep vcore under 1.4v and as you say concentrate on max FSB, then CPU speed and then finally adjust memory speed/timings.

If I do get stuck at a certain FSB, which of the above voltages will I need to adjust first and what limits do I need to stick to for each of them?

edit - sorry just seen above, NB voltage should be all I need to change if anything.
 
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If you use the above approach you should only be limited by Vcore or the chip. Assuming your motherboard will work at the chosen FSB.

On my X38 FSB was effected by using 4 sticks of ram. Basically if you have 4 sticks you will need more NB voltage over 2 sticks.
 
Only running 2 sticks so should be fine. Currently testing out 500FSB.

What was the highest stable FSB you got on your X38 board?
 
VTR said:
Only running 2 sticks so should be fine. Currently testing out 500FSB.

What was the highest stable FSB you got on your X38 board?
Click to expand...

With a Q9450 about 438. Never tried it on a Dual. That was a Maximus Formula SE.

I personally don't think you can beat the P5Q Dlx. Silly FSB speeds with very low voltage and a rock solid board.
 
OK cheers for your help.

Currently in Windows at 525FSB with default volts on everything, testing to see if it's stable now.

edit - fell over straight away. Any increase in NB voltage at this FSB and it won't post also.

Trying 500FSB all default volts now.
 
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